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<head>
	<meta charset="UTF-8">
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	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
</head>

<body>

	<script>
		function People(opt) {
			this.name = opt.name
			this.age = opt.age
			this.speak = function () {
				console.log('Can speak.');
			}
		}
		let opt = {
			name: '123',
			age: 21
		}
		let nick = new People(opt);
		console.log(nick);
		nick.speak();
		// console.log(People(opt));
	</script>
</body>

</html>